Demicompactness, selection of linear relation and application to multivalued matrix

Abstract

In this paper, we investigate the concept of demicompactness and we establish some new results in Fredholm theory connected with the existence of selections of a given linear relation and we explore the possibility of finding a selection demicompact for some linear relation demicompact. Moreover, we give the relationship of the resolvent set between the linear relation with its selection. Furthermore, we give an application to matrix linear relation.